Self-sealing test plug



Jan. 8, 1952 o. MAlscH 2,581,537

SELF-SEALING TEST PLUG Filed July 19, 1949 OLA/5@ ,14A/5CH, Y

IN V EN TOR. ?6 n l so f5 Husa/vm, BEL-HLM, Wamel., ,6 Hmz/,G a CALDWELL, 75 42 TTORNEVS. 42 410// n A Patented Jan. 8, 1952 S-ELF-SEALING TEST PLUG Oliver Maisch, Chicago, Ill., assigner to Rheem Manufacturing Company, Richmond, Calif., a corporation of California Application July 19, 1949, Serial No. 105,527

8 Claims. l

My invention relates to the art of pressuretesting containers designed to hold luidarand has particular reference to a test plug adapted to seal an open aperture in such container while fluid under pressure is introduced into the container for the purpose of testing.

In the manufacture of pressure containers, such as barrels, drums, conduits and hoses, it is often essential that each individual unit be pressure-tested before distribution to the ultimate user in order to insure that the equipment will not lose its contents by leakage or explode under use and injure any person in the vicinity or damage equipment. Where large quantities of such pressure containers are being produced, the problem of time consumed in sealing the open aperture in order to test the vessel or container becomes important. It is, therefore, one of the objects of my invention to produce a self-sealing test plug which may be readily and quickly inserted into the aperture for sealing purposes and which may be readily and quickly removed therefrom.

In testing pressure-containing equipment, it is necessary to apply a testing pressure several timeslarger than normally intended to be sure that suflicient safety factor resides in the equipment. The forces in such case tending to blow the test plug from the aperture are considerable. It is also among the objects of my invention to produce a self-sealing, test plug which utilizes the pressure being applied inside the container to effect the seal over the aperture so that regardless of the pressure applied, an equal or greater force is exerted against the sealing plug, thereby preventing a blow-out of the plug from the aperture or a leak around the sealing gasket.

I am aware that a great many test -plugs and some self-sealing test plugs have been designed and used. However, all of the test plugs of the prior art known to me have been limited in their application in that they are designed either to seal the opening of a thin-walled drum by extending an anchoring member internally of the drum or to seal the open end 'of' a conduit or tubing by engaging the side walls thereof. So far as is known to me, none of these devices are applicable to both types of pressure containers. It is a further object of my invention to provide a self-sealing test plug which is more or less universal in its application and can be used in sealing and testing either thin-walled containers or conduits and tubing.

Other and further objects and advantages of my invention will become apparent from the drawings and the specifications relative thereto.

In the drawings:

lar resilient ring 2|.

Figure 1 is a side elevation of a test plug embodying the principles my invention.`

Figure 2 is an enlarged sectional View taken on line 2-2 of Figure 1.

Figure 3 is a view similar to Figure 2 showing the plug in operating position at the end of a conduit.

Figure 4 is a sectional view taken on line 4-4 of Figure 2.

Figure 5 is a sectional View taken on line 5-5 of Figure 3. Y

Figure 6 is a fragmentary sectional view showing a modied form of my testing plug.

Figure 7 is a side elevation showing the application of my testing plug to a thin-walled container.

My invention is composed of three essential parts, namely, a sealing means, means for applying pressure to said sealing means, and means for anchoring said plug to said container.

The sealing means comprises an annular resilient ring I having a tapered face II adapted to engage the open lip of a tubular fitting I2 and to be urged in tight t thereagainst to prevent the escape of any fluid under pressure contained in the tubing.

The means for applying pressure on the sealing ring I0 comprises a cylindrical housing I5 having a closed end I6, the closed end I6 being formed with a threaded aperture I'I co-axial with the cylindrical housing I5. The cylindrical housing I5 is also formed with an L-shaped notch I8 having a horizontal and a vertical leg.

A piston I9 is disposed Within the housing I5 for reciprocation therein. The piston I9 is formed With a peripheral undercut groove 20 adapted to Vreceive a generally U-shaped annu- It should be understood that the ring 2i is in the nature of a piston ring adapted to prevent the escape of fluid under pressure between the side wall of the piston I9 and theinterior of the cylinder l5. The piston I9, the cylinder I5 and the end wall I6 cooperate to define an expandable pressure chamber 22.

The piston I9 is also formed with an axial bore 25 adapted to receive a coil compression spring 26 which abuts against the bottom of the bore 25 and end wall I8, thereby normally urging the piston I9 outwardly with respect to the cylinder I5 to form an initial seal before the application of testing pressures.

An annular groove 28 is formed in the bottom of the piston I9 and defines inner and outer annular walls 29 and 3U. The annular groove 28 is adapted to receive the resilient ring III in frictional engagement. It is to be understood that the inner annular Wall 3|) is adapted to support 3 the annular ring I from collapsing inwardly upon the application of pressure for sealing purposes.

An axial bore 32 extends inwardly in the piston I9 and is adapted to form a wall 33 between the bottom'of thebore 25 andthe bore'SZ. The wall 33`is formed with a non-circular bore 35, the purpose of which will become apparent later.

It will be readily apparent that alternativelyl the bore 32 can extend inwardly to thebore'25, and that instead of using the non-circular bore 35, diametrically opposed setscrews can be inserted through the wall of the piston I9 'to con-' tact the flat sides of the cylindrical shaft 54.

The anchoring member comprises an outer 1r shell d, which said shell is formed with a plurality of radial bores il adapted to receive cam followers, such-as balls 42. The outer edges of the bores Ll-I are peened or'upset, such as lat 43, to prevent the balls 42 from falling from-said boresl Y The shell 4I is formed with an axial-bore 44 adapted to receive a cam head 45. The-cam head L15-isv formedwith a plurality ofcam surfaces 46 adapted to receive a portion of the ball 42wh'enin vproper position. It-will be readily understood that respective rotation between-the cam head-45 'and thefshell dwill ycause the-'cam followers to move outwardly from thecarnsurfaces 45, as isy shown in vFigure 5, thereby expanding the effectivediameter ofthe anchcr head'.

Thee-cam head 45 isformed with a shaft 5t havingareduced diameter, thereby dening a shoulder 5I.` The upper end of the shaft50-is threaded and adapted for threaded engagement in the bore I1,- which said engagementtogether with a lock nut 52 prevents-rotation ofthe cam head with vrespect tothe housing I5.

The shells@ is forrnedfwithan upwardly'extending cylindricalV shaft 5ft co-axial withf the .fi

shaft'-50,-whichsaid shaft isvformed withla 'noncircular-end 55 complementary withthefnon-circular aperture 35 and is adapted to'fbe-slidably disposed?- therethrough and heldin position by snapi ring'56; It, therefore,-becomes apparent that-the-piston I9 Canrecip'rocate with respect to the-shell 5 40,- but may.` not .rotate with respect thereto.'l Y

Therefore, rotation of the piston I9 withrespect to the cylindrical housing. I5 will cause a rotation of the cam head45 with respect. to the shell @45; which said rotation will causean expansionof the balls- 132, thereby engagingror anchoringqagainst the endwall-of flange, tube or tting. Y

AMeans is provided ,for guidingsuch rotation between the piston I3 andthe cylinder I5. Such means comprises aT pin BI]V adapted to extend outwardly from said piston I9 through the L-shaped slot I8.

Itwill, therefore, readily be seen that the-anch'orin'g head of theshell 5U-can" bey inserted into an opening whereupon the pin 60' is rotated in the'slot I8 until it reaches the vertical leg; VThe' rotation of the pin 6'0 in thev slot l'causes the expansion ofthe'ballsv 42 outwardly to engage the' endof thesle'eveor' tubular fitting I2. The'cornpression spring 25u causes a movement of the piston I9 longitudinally outward from th'ecylindric'al housing I5 to ,cause engagement between'the sealing ring III` and theup'per peripheryof the fitting I2.

It'will be notedthatclearance is provided-between thepiston I9 andthe shaftl54,so thata'nyl,

will be transmitted through the passage defined by this clearance of the interior of the chamber 22 where pressure will further tend to cause separation between the top I5 and the piston I9, so that as the pressure is increased inthe tubular tting I2, thepressuredownwardly. on the sealing 'member 'I Il' will be increased.

In the modication illustrated in rFigure 6,

` similar numerals to those shown in Figures 1-3,

inclusive, indicate similar parts. The principal modication lies in the fact that the cylindrical housing v I 5 extends upwardly past the end wall I6 and is threadedinternally as at 'lil adapted to receive a Vpressure hose. The end wall I6 is formed with aplurality of apertures l! to permit theV passage of fluid under pressure into the chamber 22 to eiTect a sealing engagement with the top of the tubular fitting I2 and also to permit the' passage-of said fluid Vfrom the chamber 22 intol theinterior'v of the tubularfittin'g I2 through the clearance between the shaft 54 and thel piston I 9.

Figure 7 illustratesmy test plug in-use for sealing an aperture in a relatively thin-walled container. In Figure-7 Ihave illustrated the expandablehead as being inserted through athreadedafperturel 'l5 of--a thin-walled vessel 76: A4 tubular member TI is faxially'disposed with respect Atovthefsha'ft 54andis provided with aperipheral-shoulder 'lhaving an internal annular undercu-tgroove 'I9 adapted Jto-receive a resilient gasket 80. The resilient gasket AE35 is adapted to engage the-upper 'surface of the containerimmediately'surrounding the aperture I5 for sealing said aperture against the escape of fluid under pressure fin' the container.

Theupper rimof the tubular member 'VI is adapted-to abut against the angular face II- of the resilient ring I0.

The expandable head'member is first inserted through the aperture 'I5 and the pin 60 is rotated in the-slot I8 with respect-toA the housing I5, thereby causing a rotation between theshell member 4I] and the cam head'45- causing thea-balls 42 to move outwardly. Whenthe balls `I2V have moved toI their'ou-teriextreme limits, they dene a circlerhaving a diameter larger than the diameter of the aperture 'l5 `so'that the -cam or expandable head cannot' be `withdrawn `through the aperture l5;A Pressure isI then appledin the lmanner above describedcausing the pistonl I9 to'movedownwardlywith respect tothe housing'l5 to eiectively sealboth the uppery and lower endsfof thel tubula'rf'mernber 11; It will readily be apparent that as greater pressures-are applied internallycf the vessel, `agreater' force will'be` appliedto' the sealing-"of both-ends of the tubular memberll because the! pressure contained-inthe vesselis but' is to Vbe accorded the full scope ofthe claims so as to' embrace any and all equivalent devices.V

Having described my invention, what I claim as new-V and desire -to secure b'yLettersPatent--isz 1. In a" self-sealing test plug adapted to seal Y Y. l t an'aperture ina container"during pressure-test'- pressure appliedL insideof` the tubularY fitting I2 ing thereof, said test plug having apistonand cylinder assembly deiining'an expandable pressure chamber, resilient sealing meansdisposed on said piston adapted to engage the peripheral edges of said aperture to seal said aperture against the escape of fluid under pressure, and holding means adapted to engage the inside of said container to hold said test plug in sealing relation with respect to said aperture, the element 0f novelty residing in said holding means and comprising a cam secured to said cylinder, a plurality of cam followers adapted to be radially displaced into expanded or contracted position upon rotation of said cam with respect to said cam followers, and means slidably but non-rotat ably associated with said piston adapted to restrain displacement of said cam followers circumferentially about the axis of said cam upon rotation of said cylinder with respect to said piston.

2. In a self-sealing test plug adapted to seal an aperture in a container during pressure-testing thereof, said test plug having a piston and cylinder assembly defining an expandable pressure chamber, resilient sealing means disposed on said piston adapted to engage the peripheral edges of said aperture to seal said aperture against the escape of fluid under pressure, and means adapted to engage the inside of said container to hold said test plug in sealing relation with respect to said aperture, the elements of novelty including said holding means and comprising a cam secured to said cylinder, a plurality of cam followers adapted to be radially displaced into expanded or contracted position upon rotation of said cam with respect to said cam followers, means slidably but non-rotatably associated with said piston adapted to restrain displacement of said cam followers circumferentially about the axis of said cam upon rotation of said cylinder with respect to said piston, and means associated with said piston adapted to guide rotation of said piston with respect to said cylinder.

3. In a self-sealing test plug adapted to seal an aperture in a container during pressure-testing thereof, said test plug including a pair of members, one a cylinder, the other a piston therein defining an expandable pressure chamber, resilient sealing means disposed on one of said members adapted to engage the peripheral edges of said aperture to seal said aperture against the yescape of fluid under pressure, and means adapted to engage the inside of said container to hold said test plug in sealing relation with respect to said aperture, the elements of novelty including said holding means and comprising a cam secured to the other of said members, a plurality of cam followers adapted to be radially displaced into contracted or expanded position upon rotation of said cam with respect to said cam followers, means slidably but non-rotatably associated with said one member adapted to restrain displacement of said cam followers circumferentially with respect to said one member upon rotation of said cam, means associated with said members to guide rotation of one member with respect to the other member, and resilient means disposed between said members adapted to cause axial displacement of said piston with respect to said cylinder after said cam followers have reached maximum expanded position for initially sealing said aperture before the application of pressure thereto.

4. A self-sealing test plug adapted to seal an aperture in a container during pressure-testing thereof comprising a piston and cylinder assembly defining an expandablepressure chamber, said piston being formed with inner and outer concentric annular walls at the outer end thereof defining an annular groove, resilient sealing means disposed in said annulargroove and adapted to engage the peripheral edges of said aperture to seal said aperture against the escape of fluid under pressure, means adapted to engage the inside of said container to hold said test plug in sealing relation with respect to said aperture, said holding means comprising a cam secured to said cylinder, a plurality of cam followers adapted to be radially displaced into expanded and contracted position upon rotation of said cam with respect to said cam followers, means slidably but non-rotatably associated with said piston adapted to restrain displacement of said cam followers circumferentially about the axis of said cam upon rotation of said cam, means associated with said piston adapted to guide rotation of said piston with respect to said. cylinder, and resilient means disposed between said piston and cylinder adapted to cause axial displacement of said piston with respect to said cylinder after said cam followers have reached maximum expanded position for effecting an initial. seal between said sealing means and the peripheral edges of said aperture before the application of testing pressure thereto.

5. A self-sealing test plug adapted to seal an aperture in a container during pressure-testing thereof, said test plug having a piston and cylin der assembly defining an expandable pressure chamber, said piston being formed with inner and outer concentric annular walls at the outer end thereof defining an annular groove, said inner wall being relatively higher than said outer wall, resilient sealing means disposed in said annular groove adapted to engage the peripheral edges of said aperture to seal said aperture against the escape of fluid under pressure, means adapted to engage the inside of said con-- tainer to hold said test plug in sealing relation with respect to said aperture, said holding means comprising a cam secured to said cylinder, a plurality of cam followers adapted to be radially displaced into expanded or contracted position upon rotation of said cam with respect to said cam followers, means slidably but nonrotatably associated with said piston adapted to restrain displacement of said cam followers circumferentially about the axis of said cam upon rotation of said cam, and means associated with said piston to guide rotation of said piston with respect to said cylinder.

6. A plug for sealing an aperture having inner and outer edges in a container during fluid pressure-testing comprising an anchor member formed with a head adapted to be inserted through the aperture and to be expanded after insertion to engage the inner edge of the aperture, a resilient annular gasket around said anchor member, said annular gasket having an outside diameter larger than the diameter of the aperture and adapted to be compressed against the outer surface of the container adjacent the periphery of the aperture, a housing having relatively movable end elements defining an expandable pressure chamber, said anchor member being secured to one of said end elements, said gasket being secured to the other of said end elements, means defining fluid communication between said container and said chamber Whereby fluid pressure introduced into the container will cause relative movement of the end ele- Y mentsfand nirgefsaidzgasketand the headrosad anchormemberrtogetherftoieffectLarpressure seal. across they aperture,` saidgan'chormembencomf prising.y azcam membenhaving. vcamming.. surfaces thereon and. av .campfollowenassociated with; each.

ture, Aa resilient: annular gasket. .around said .an-:- -1

chor member; said; gasket having an 'outside diameter larger than thediameteroffthe aperture and adapted to:becompressedagainstzthe outersurfacelof the container. adjacent the. periphery'ofV the'- aperture to eiecta sealing engagement therewith; a-housing having-relatively movable `end elements 'dening an expandable pressure`r chamber, said anchor member` being secured to one` of saidend'a elements, saidgasket beingA securedtothe other of said4` end elements, andV meansV` dening fluid communication between saidcontainer and saidchamber whereby "fluid pressure 4introduced into the container will cause re1ative movement of-'theend elements and-urgev said=gasket and' the headof said f anchor member together toeecta pressure seal acrossA thefvaperture, said anchorvmember comprising a substantially:cylindrical head having an axialY bore thereinfand' a pluralityof radial bores ntersectng'saidaxial bore, a cam head rotatably disposedin-sa-id 'axial bore and non-rotataloly4 secured to one of saidiend` elements, a cam` follower reciprocally disposed in each of said radial bores, said cam head being formedwith a cam surfaceadapted to cooperate with each'of'said cam followers, and means associatedwith the endfelem'entgother than the one mountingf; said f. cam; lfleadf` adapdr; 159s GaRSQsIQsf tationeoffsaid-.ecam followersfiw' hzresnee tezsaidz 81' Avplug'ffrz. Sealing an i aperture.: ui c.

- rainer, during uidlpressure testing Comp.

in combination: s enganchar; member; edasted aperturesasainst .eseapee T1111. ,a ingfrelatvelyv mutable Iwalls. f delnms emessi@ sible pressure chamber, said anchor member-bef.. inezsecuredfto: one of Seid Wallsz Seidzghslit bings. secured.. to.v the. other.r of.: said; Wells, andi a. nui-.d passageway disposed .te Communicate be.- tween .the container and sa d @..haxxlbe if udunderfnressure..fro chamber; .therebyeexpandms-.S idr/h pressing` Said: gasket ntsm; engagement .with the, container.

' REFERENCES f crrED The Y following references. are ;of lrecord I-in@` the filev of this i patent: Y

UNITED.. STATES. PATENTS. 

